Process for burning lime or other substances.



I PATENTED AUG. 6, 1907.

APPLICATION FILED MAY 18, 1907.

y WW

Witnesses JAMES REANEY, JR, OF SHERWOOD, MARYLAND.

PROCESS FOR BURNING LIME OR OTHER SUBSTANCES.

Specification of Letters Patent.

Patented Aug. 6, 1907.

Application filed May 16, 1907. Serial No- 373,994-

To all whom it may concern:

Be it known that 1, JAMES REANEY, .Ir., a citizen of the United States,residing at Sherwood, in the county of Baltimore and State of Maryland,have invented certain new and useful Improvements in Processes forBurning Lime Rock or other Substances, of which the following is aspecification.

This invention relates to an improved method or process for burning limerock or other substances.

At the present time lime rock or other substances to be burned areplaced in a kiln and subjected to heat, and the burning operation isconducted until the particles are deemed to be sufficiently burned. Themanner of determining the sufficiency of the burning period varies,according to the kind or style of kiln employed. In the case of astationary kiln the particles all remain in the heating zone for a givenperiod and are then all removed at the same time. In the case of arotary kiln the movement of the particles through the kiln is timed, butin all cases all the particles are exposed to the heat for practicallythe same given period. These methods of burning result in some of therock material being overburned and some underburned, because all theparticles are treated alike in that they are all subjected to the heatfor a definite period. If the burning operation is timed so as to insurethat all the particles will be burned, then some of the particles willbe overburned.

It is a fact that many lime rocks and other materials, differ greatly intheir natural formation, both in density and in their chemicalcomposition, even when obtained from the same quarry, and thisdifference makes it necessary in order to produce a product ofuniformity, that the particles should be treated individually, so tospeak, instead of collectively, as heretofore.

By my improved method, or process, the particles, although differinggreatly in their chemical composition or for other reasons requiring,some, more burning and some less burning, may all be burned to suittheir particular requirements, in that as they become sulficicntlyburned, they are removed from the burning .zonc, while other particles,which burn more slowly,

are retained in the burning zone.

In the burning of lime rock and other materials portions of thecomponent parts are given up in-the form of gas, when heat of a propertemperature is applied, the gas or gases passing off with the productsof cornbustion, and the particles change in weight and become lighter asthe burning progresses. It is this change in the weight of the particlesthat I utilize to carry out my process and as the change gradually takesplace, I am enabled to produce a product of a uniform character,irrespective of the difference in the character of the material beforetreatment.

In order that the process may be conducted continuously andautomatically, I prefer to employ a rotary kiln, but it is to beunderstood that the process may be conducted in other ways and by anapparatus differing widely from that shown in the accompanying drawing,forming part of this specification.

The accompanying drawing shows a longitudinal sectional view of one formof apparatus which will be briefly described.

Referring to the drawing by numerals, 1, designates a suitable base orsupport having suitable rollcr bearings, 2, at opposite ends whichlatter sustain a cylinder, 3, in an inclined position,that is, one endof the cylinder being higher than the other end. This cylinder isprovided with exterior metal rings or bands, 4, which travel on therollers in the bearings, 2. The cylinder may be of any desiredconstruction, having an interior fire-proof lining, 5, and at a pointpreferably midway between its ends is provided with an exterior circularrack, 6. A pinion, 7, is mounted on a shaft, 8, beneath the cylinder andsaid pinion meshes with the rack, 6, and causes the cylinder to berevolved. A stationary head, 9, is provided at the higher end of thecylinder and is sustained in any preferred manner, and a chute, 10,extends downwardly through the stationary head with its lower end, 11,terminating inthe upper or higher end of the said cylinder. Above thecylinder at any suitable point, I provide a hopper, 12, into which thelime rock or other substance to be burned is 1 placed and at the lowerend of said hopper I provide a suitable conveyor, 13, which carries orconveys the rock from the hopper to the upper end of the chute, 10. Amain driving shaft, 14, extends beneath the cylinder and carriesa bevelpinion, 15, which latter meshes with a bevel gear, 16, on the shaft, 8,so as to revolve the latter. The lower end of the cylinder is alsoprovided with a stationary head, 17, having a vertical passage, 18,through which the products discharged from the cyl inder pass. Aproducer gas apparatus, 19, of any wellknown construction, or other heatproducing medium, is provided at the lower end of said cylinder and thisgas apparatus, in the present instance, is provided with a tube, 20,that projects through said head, 17, and directs the heating agent intothe lower end of the inclined cylinder, 3, where it ignites. An airchamber or drum, 21, surrounds the lower end of the discharge passage,18, and is provided with air admission ports, 22, while a screwconveyer, 23, is located at the lower end of said .chamber, or drum, soas to convey the discharged product laterally and deposit it upon asuitable conveycr, 24.

Air passages, 25, are provided around the chamber or drum which latterbecomes heated by the product passing through the passage, 18. Theheating of this drum serves to heat the air as it travels up through thepassages, 25, and before it commingles with the pro (lucer gas in tube,20, after which the combustion takes place.- A valve, 26, may be placedin the air I of the kiln.

passages, 25, to enable the regulation of the quantity of air,v while avalve, 27, in the gas tube will govern the quantity of gas or otherheating agent. A rotary cooler may be used in place of the above deviceand the air heated as it passes through at the same time cooling theheated lime, or other material.

At the upper end of the cylinder, 1 provide a suitable apparatus, 28,such as a rotary fan, which will draw the heat and products ofcombustion from the lower end of the cylinder out through the upper endthereof. If desired, the products of combustion passing from the upperend of the cylinder may be conveyed to a boiler and utilized in thegeneration of steam, thus working out economies in the operation of theapparatus.

The interior of the fire-proof cylinder, which in reality is the kiln,is provided with a plurality of inwardly projecting fire proof rings,30, or other suitable projections which will serve to dam or check thepassage of the lime rock, or other material, in its passage from thehigher to the lower end of the cylin-' drical kiln. The form and numberof these projections, rings, or the like, may vary, but in the presentinstance the kiln is provided with four rings which form successivecylindrical compartments, 31, 32, 33, and 34, the latter being at thelowermost end Each of these rings serve as abntinents, or dalns, againstwhich the rock, or material under treatment, may be checked in itsdownward course through the kiln, while the heat acts on it to properlyburn it.

The lime rock or material to be burned is first crushed to the propersize and then placed in the hopper, 12, from which it is conveyed by thescrew, 13, to the upper end of the chute, 10. The rock, or material, isthen conveyed by the chute and discharged into the compartment, 31, inthe rotary kiln and behind the partition ring, or dam, 30, where it istumbled, or agitated, while it begins to heat and drive off any moisturethat might be contained in the same. As the burning of the crushed rock,or material, progresses, it parts with its gases, some particles orlumps however being larger than others will require more time beforecompleting this operation, but as the gases pass off, some slowly, andsome faster, the particles lose correspondingly in weight, or density.By reason of this change in the weight of the particles, I am enabled toinvoke the operation of gravity, to separate the lighter partiallyburned particles from those that are heavier and less advanced in theirburning operation and in order to effect this gravity separation, Iprovide the partition ring or dam, 30 between the compartments, 31, and32.

It is a well-known fact that if a quantity of matter consisting ofparticles which vary in weight is placed in a receptacle and the latterthen shaken, the lighter particles will gradually work to the surface.By thus applying this same principle tomy method of burning lime rock orother material, I am enabled to separate the lighter burned particlesfrom the heavier unburned particles, and by providing the partitions 30,between the several compartments, the heavier.

unburned particles at the bottom of the mass are held in check, whilethe lighter particles on the surface, may pass off, by flowing over thedams. It is therefore to be understood that the particles in thecompartment, 32, are lighter than the particles in compartment, 31,.andthat as the tumbling, agitating, or other motion imparted to theparticles in the said compartment, 32, is continued, they will back upbehind the rings, or dams, so that again the particles more advanced intheir burning operation, and therefore lighter in weight, will rise tothe surface and pass off into the compartment, 33.

As the particles advance in their burned condition they also advancefrom one compartment to another and no matter how ununiform they may bewhen they enter the kiln, they only advance their position in the kilnas their burning operation progresses. More over, as the particlesprogress in their burning operation, they advance faster and travel morequickly from one compartment to another, and when finally discharged theproduct is of a uniform character. It will therefore be seen that theperiod, or length of time, that the particles remain in the kiln variesaccording to the condition of the particles themselves, each particlebeing individually treated according to its requirements and the processof burning being conducted automatically by invoking the law of gravity.Longitudinal projections or flights, 36, are provided in the severalcompartments and these flights being attached to the rotary kiln orcylinder, travel therewith, and as they pass beneath the mass, they dragout the heaviest unburned particles from the bottom of the mass andcarry them upwardly through the hottest part of the compartment and thendrop them. These particles drawn from the bottom of the mass in anygiven compartment, are the heaviest particles in that compartment, andas they are being elevated by the flights so as to be exposed to thedirect blast of the heat, most of them will roll back down the curvedwall of the cylinder and work beneath the surface of the mass, whileothers will drop from the flights through the heat and disappear beneaththe surface of the lighter particles. This action on the heaviestparticles, causes the latter to be properly burned and as they becomeburned, they break up and get lighter and thus rise to the surface,Where they pass off into the next compartment.

As the burned particles discharge from the kiln, they pass down throughthe passage, 18, and the heat therefrom is utilized to heat the air thatis continually passing up through the passages, 25, to mix with theheating agent. I

It will be seen that the process may be condu cted continuously andautomatically.

Having thus described my invention what I claim as new and desire tosecure by Letters'Patent is,

1. The process of burning lime rock or other material, consisting inagitating the material in the presence of a burning heat and during theagitation separating by gravity the heavier unburned particles whichsettle to the bottom from the lighter burned particles which rise to thesurface of the mass and removing the lighter separated particles from"the surface.

2. The process of burning lime rock or other material, consisting inagitating the material in the presence of a burning heat, holding thematerial in check during agitation to enable the heavier particlesthereof to settle to the bottom of the mass and the lighter particles torise to the surface, and then removing the. lighter particles from thesurface of the mass.

3. The process of burning lime rock or other material, consisting inagitating the material in the presence of heat sufiicient to burn it,separating by gravity the more advanced burned particles from the lessburned particles, and holding in check the less burned particles whilepermitting the more advanced burned particles to pass 0E.

4. The process of burning lime rock, or other material, consisting inagitating the particles in the presence of a burning heat, holding themass in check to permit the unburned particles to settle and thepartially burned particles to rise to the surface, then removing thepartially burned particles from the surface of the mass and againholding them in check while the burning continues and again permit theless advanced burned particles to settle and the more advanced burnedparticles to rise to the surface.

The process of burning lime rock, or other material,

consisting in agitating the particles in the cooler end of a heatedreceptacle, to gradually eat them and drive off any moisture, holdingthe mass in check to permit the heavier unburned particles to settle tothe bottom and the lighter partially burned particles to advance to ahotter portion of,the receptacle, again holding the particles in checkto permit the lighter more advanced burned particles to rise to thesurface and continuing this intermittent checking and separation of theparticles by gravity until the particles are burned.

In testimony whereof I affix my signature in presence HOWARD D. ADAMS,ROLAND H. BRADY.

